Lug wrenches typically include a socket for receiving a lug nut (wheel nut) and a handle extending from the socket. The handle has a length sufficient to permit a person to manually apply a sufficient levered force to the socket to tighten or loosen a lug nut. Various lug wrenches are well known in the art.
Such lug wrenches are often sold as tools in auto supply and hardware stores, and at car shows or similar exhibitions. Additionally, many auto manufacturers include a lug wrench as original equipment in a tool kit of their vehicles.
One popular style of lug wrench is the L-shaped lug wrench. Such lug wrenches typically have a handle extending at an oblique angle with respect to the socket's axis to help avoid interference of the handle with the wheel, tire, or ground while loosening or tightening a lug nut of a vehicle's wheel.
Pneumatic or other power-driven equipment typically used by auto mechanics, auto manufacturers, etc. often applies more torque to a lug nut than many motorists can easily apply with a conventional lug wrench, e.g. approximately 120 ft-lbs. This makes it particularly difficult for such a motorist to loosen lug nuts to remove a wheel from the motorist's vehicle.
This difficulty is particularly acute with the L-shaped lug wrench because the L-shaped handle and the angle of the handle relative to the socket's axis. These features cause the application of turning force to the socket and nut to be unbalanced. This tends to cause the lug wrench to slip off of the lug nut and/or inhibits application of sufficient torque before slipping off of the nut.
To overcome this difficulty, various T-shaped lug wrenches have been manufactured in which handle portions extend substantially equal distances from and transversely to the axis of a rod bearing the socket. Various X-shaped wrenches (cruciform or cross wrenches) are known that provide differently sized sockets at each end of the wrench. Such T and X wrenches allow for a more balanced application of turning forces to a lug nut. See U.S. Pat. Nos. 1,282,028, 1,630,848, 2,738,694 and 3,587,366.
However, such T and X wrenches fail to provide an ergonomically sound wrench that provides a sufficient degree of balance for efficient application of turning force to a lug nut.